Back Discharge Ionic Wind and this Ionic Wind Effect for Dust Particles in an Electrostatic Precipitator

Ionic Wind (IW) is one of the collecting forces and has an effect of the behaviors of particles in an electrostatic precipitator (EP). Back discharge IW occurs by Back discharge is a kind of IW and many problems for this IW in EP have been unsolved so for. In this experiment, the model EP is a discharging needle or one discharging wire-to-Mica plate electrode system. Mica is used in place of the dust layer with high resistivity and has some pinholes to occur Back discharge in model EP. In the first place, authors observed Back discharge IW by using Schlielen equipment because of being not able to observe it directly. Next, three kind of particles (joss-stick, polyethylene, lycopodium) were put in EP and the behaviors of particles within Back discharge phenomena were observed. As a result, Four flow pattern of Back discharge IW in EP could be classified by analyzing behaviors of joss-stick smoke and the reentrainment behaviors of lycopodium and polyethylene particles were different from the particle behaviors in nomal state without Back discharge. Particle speed jumping from Mica plate electrode was larger than collecting speed by the cause of repulsing Coulomb force and Back discharge IW force. It is thought that Back discharge IW has large effect on the behaviors of particles in EP and is one of the causes by which collecting efficiency decrease in Back discharge state in EP.